Nord Lock Bolt Securing System

The NORD-LOCK bolt securing system uses geometry to safely lock bolted joints in the most critical applications. This unique wedge-locking system offers the following advantages:

Maximum safety

Resists loosening caused by vibration and dynamic loads

Ease of assembly and disassembly

Locking function is not affected by lubrication

Positive locking at low and high preload levels

Controllable preload

Same temperature characteristics as standard bolt/nut

Reusable

Tension makes the bolt self-lockingThe key is the difference in angles. Since the cam angle " a " is larger than the thread pitch " ß ", the pair of washers expand more than the corresponding pitch of the thread. NORD-LOCK washers positively lock the fastener in a joint which is subjected to extreme vibration or dynamic loads.Locking Functions

NORD-LOCK is a pair of washers with a wedge-locking action meeting DIN 25201 which is a unique method using tension instead of friction. The rise of the cams between the NORD-LOCK washers is greater than the pitch of the bolt. In addition, there are radial teeth on the opposite side. The washers are installed in pairs, cam face to cam face.

When the bolt and/or nut is tightened the teeth grip and seat the mating surfaces. The NORD-LOCK washer is locked in place, allowing movement only across the face of the cams. Any attempt from the bolt/nut to rotate loose is blocked by the wedge effect of the cams.

Here you see what happens when a bolt is untightened with a wrench. The pair of washers expand more than the corresponding pitch of the thread allows the bolt/nut to rise.

NORD-LOCK washers positively lock the fastener in a joint which is subjected to any kind of vibration or dynamic loads.